1. Field of the Invention
The present invention relates to a turbocharger with an electric motor. More particularly, the present invention relates to a turbocharger with an electric motor that includes an electric motor, a housing receiving the electric motor therein, and a current supply path, such as a cable, extending from a motor stator of the electric motor to the outside of the housing.
2. Description of the Related Art
A turbocharger is an apparatus that is driven by exhaust gas from engine, compresses intake air, and supplies the compressed air to the engine.
A turbocharger is disclosed in, for example, in Patent Document 1. FIG. 1 is a schematic view of a turbocharger with an electric motor of Patent Document 1. As shown in FIG. 1, as basic structures, the turbocharger includes a turbine impeller 71 that is rotationally driven by exhaust gas from an engine, a rotating shaft 75 of which one end is fixed to the turbine impeller 71, and a compressor impeller 77 that is integrally rotated with a turbine impeller 71 fixed to the other end of the rotating shaft 75. In this structure, the turbine impeller 71 and the compressor impeller 77 are integrally and rotationally driven by the exhaust gas from the engine, so that the compressor impeller 77 compresses intake air and supplies the compressed air to the engine.
Among turbochargers, a turbocharger in which an electric motor is built therein is referred to as a turbocharger with an electric motor. The turbocharger of FIG. 1 is a turbocharger with an electric motor. As shown in FIG. 1, an electric motor 79 assists a rotating shaft 75 in accelerating, and increases the amount of compressed air supplied from the compressor impeller 77 to the engine. Further, the electric motor 79 includes a motor rotor 79a that is fixed to the rotating shaft 75, and a motor stator 79b that is fixed to the housing 81 outside the motor rotor 79b and rotationally drives the motor rotor 79a. 
The motor stator includes coils that generate a magnetic field used to rotationally drive the motor rotor, and a plurality of coils is arranged in a circumferential direction along a circle that has an axial center of the rotating shaft as a center thereof. In order to supply current to these coils, a cable is wired so as to be connected to the coils and then wired to extend to the outside of the turbocharger. This wiring structure is disclosed in, for example, Patent Documents 1 to 3.
In Patent Document 1, as shown in FIG. 1, a connector 85 is attached to a motor stator 79b, and a wiring hole 87, which is used to guide a cable connected to the connector 85 to the outside of the turbocharger, is formed in a housing 81.
In Patent Document 2, as shown in FIG. 2, a wiring hole 93, which is used to supply current and electric power to a motor stator 91, extends in an axial direction, and is opened at a compressor housing 94.
In Patent Document 3, as shown in FIG. 3, a wiring hole 98, through which a cable 97 passes in order to supply current to a motor stator 95, is formed in a housing 99.
Patent Document 1: PCT Japanese Translation Patent Publication No. 2006-514526
Patent Document 2: WO 2005/024202 A1
Patent Document 3: WO 98/02652
However, in Patent Documents 1 to 3, the wiring hole is positioned at one position in the circumferential direction. For this reason, the position of the opening of the wiring hole cannot be adjusted on the housing in the circumferential direction in accordance with the structure of the engine on which the turbocharger is mounted.
That is, since the take-out position of the cable on the housing is limited to one position in the circumferential direction, the take-out position of the cable needs to be changed in some engines on which the turbocharger is mounted. For example, the structure of the engine on which the turbocharger is mounted closes up the take-out position of the cable, so that the cable may not be taken out at the take-out position. In this case, whenever the take-out position of the cable needs to be changed in the circumferential direction, separate turbocharger parts, of which the opening of the wiring hole serving as the take-out position is formed at different positions in the circumferential direction, need to be prepared.